1. Field of the Invention
The present invention relates to an improvement of a mouse mechanism and, more particularly, to an improved optical mechanism of an optical mouse.
2. Description of Related Art
In typical optical mouse techniques, the operation principle essentially determines motions of an optical mouse by judging an uneven or micro-scraggy surface of a use plane (for example, a desk surface or a mouse pad).
With reference to FIGS. 1 and 2, a typical optical mechanism is implemented inside an optical mouse 5 in which the reflecting light is schematically shown. The typical optical mechanism includes a light device 51, a light guiding device 52 and a photosensor 53. The light guiding device 52 has a first lens 521, a second lens 522, a first prism 523, a second prism 524 and a cavity 525. The light device 51 emits an incident light I2 to the first lens 521. The incident light I2 is then reflected by the first prism 523 and the second prism 524 to pass through a bottom opening 50 of the optical mouse 5 and project on a reflective plane 6. Because the reflective plane 6 is uneven, a reflecting light R2 formed after the incident light I2 reaches the reflective plane 6 will be scattered and repeatedly reflected between the cavity 525 and the reflective plane 6. In this case, the reflecting light R2 to the second lens 522 is guided to the photosensor 53 for judging the status of the plane 6 and thus determining motions of the optical mouse 5.
However, in the cited optical mechanism, because the reflecting light R2 is repeatedly reflected between the cavity 525 and the reflective plane 6, the photosensor 53 receives not only the reflecting light R2 firstly reflected by the reflective plane 6 but also light repeatedly reflected. Accordingly, light contrast is reduced so that the optical mouse 5 does not easily determine existence of uneven or micro-scraggy in the reflective plane 6.
Therefore, it is desirable to provide an improved optical mechanism to mitigate and/or obviate the aforementioned problems.